Discharge device



Feb. 20, 1940. E. GERMER DISCHARGE DEVICE Filed Nov. 30, 19's? R o T N w W a M f Patented Feb. 20, 1940 L STATES PATENT OFFICE 2,190,557 DISCHARGE DEVICE Edmund Germer, Berlin-Wannsec, Germany Application November 30, 1937, Serial No. 117,210 In Germany December 1, 1936 1 Claim.

cylindrical tubes which are heated too much in the middle during operation; =hereby materials which are very heat resistant like quartz are deteriorated so that in a very short time they become milky and get less light transparent; especially the ultra-violet output is exceedingly decreased. It might even happen that the material .is attacked so much that it may be easily cracked.

The following described invention solves the problem by taking care of making the temperature all over the length of the tube during operation more, or completeLv, uniform, so that an overheating at several points, especially in the middle cannot take place.

This overheating depends on the position in .Which these lamps are burnt. Three different 80 types of lamps are described in the drawings, 1, 2 and 3; These drawings show only examples and demonstrate only the principal characters oi. the invention. 7 y In Fig. 1 is shown the cross section of a lamp which is'to be burnt in horizontal position. I indicates the lower wall of the tube, 2 the upper wall of the tube which is formed according the arcuate shape of the discharge at very high pressures, 3 and 4 are the selfheating electrodes which may be activated, 5 and 6 are the lead in wires or ribbons, I and 8 are metaLprovisions, consisting of mercury, cadmium", zinc or alloys or also other suitable materials, 9 and 1,0 are beads covering the lead in wires or the ribbon. I

The lead in wires and the covering beads are bent downward so that they are not attacked much by the heat generated by the intensive dis- 6 charge. It is also possible to melt the lead wires through the lower wall of the tube, in order to avoid any influence of heat convection from the discharge. I

Fig. 2 demonstrates in cross section a tube 1 which shall be burnt in vertical position. Here both sides of the wall are bulged in the middle,

so that the temperature all over the whole surface of the tube is very uniform. This figure however relates only to lamps with a small input;

For lamps with a higher input Fig. 3 shows how to bulge the upper end of the tube which is heated more by the uprising heat.

The three figures show that one has to use exceedingly thick walls of quartz material in order 20 to resist the high temperatures of about 700 C. which produce pressures of about atms.

What I claim is: a

A vapor arc device which comprises a sealed tube having an interior bore smaller than would 25 be occupied by an arc burning unconfined under conditions similar to those attainable within the tubeduring continuous operation, whereby said tube is adapted to confine the arc therein, solid activated electrodes fixed at opposite ends of said tube, the bore of the tube being enlarged near a point at which heat of the arc tends to I concentrate'and having its center line curvd upwardly between the electrodes, in-lead connections to the electrodes sealed through the tube, 86 in a diagonally downward direction, whereby they are removed from excessive heating by. the arc,

' and a filling adapted to provide an atmosphere for carrying the are which includes a vaporz abie material adapted by its evaporation to increase 40 the pressure in the tube several atmospheres.

' EDMUND GERMER. 

